/* multiboot.h - Multiboot header file. */
/* Copyright (C) 1999,2003,2007,2008,2009  Free Software Foundation, Inc.
*
*  Permission is hereby granted, free of charge, to any person obtaining a copy
*  of this software and associated documentation files (the "Software"), to
*  deal in the Software without restriction, including without limitation the
*  rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
*  sell copies of the Software, and to permit persons to whom the Software is
*  furnished to do so, subject to the following conditions:
*
*  The above copyright notice and this permission notice shall be included in
*  all copies or substantial portions of the Software.
*
*  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
*  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
*  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL ANY
*  DEVELOPER OR DISTRIBUTOR BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
*  WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
*  IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/

#ifndef MULTIBOOT_HEADER
#define MULTIBOOT_HEADER 1

#include <stdint.h>

#define MULTIBOOT_SEARCH                      8192 // How many bytes from the start of the file we search for the header.
#define MULTIBOOT_HEADER_MAGIC          0x1BADB002 // The magic field should contain this.
#define MULTIBOOT_BOOTLOADER_MAGIC      0x2BADB002 // This should be in %eax.
#define MULTIBOOT_UNSUPPORTED           0x0000fffc // The bits in the required part of flags field we don't support.
#define MULTIBOOT_MOD_ALIGN             0x00001000 // Alignment of multiboot modules.
#define MULTIBOOT_INFO_ALIGN            0x00000004 // Alignment of the multiboot info structure.

// Flags set in the 'flags' member of the multiboot header.
#define MULTIBOOT_PAGE_ALIGN            0x00000001 // Align all boot modules on i386 page (4KB) boundaries.
#define MULTIBOOT_MEMORY_INFO           0x00000002 // Must pass memory information to OS.
#define MULTIBOOT_VIDEO_MODE            0x00000004 // Must pass video information to OS.
#define MULTIBOOT_AOUT_KLUDGE           0x00010000 // This flag indicates the use of the address fields in the header.

// Flags to be set in the 'flags' member of the multiboot info structure.
#define MULTIBOOT_INFO_MEMORY           0x00000001 // Is there basic lower/upper memory information?
#define MULTIBOOT_INFO_BOOTDEV          0x00000002 // Is there a boot device set?
#define MULTIBOOT_INFO_CMDLINE          0x00000004 // Is the command-line defined?
#define MULTIBOOT_INFO_MODS             0x00000008 // Are there modules to do something with?

// These next two are mutually exclusive
#define MULTIBOOT_INFO_AOUT_SYMS        0x00000010 // Is there a symbol table loaded?
#define MULTIBOOT_INFO_ELF_SHDR         0X00000020 // Is there an ELF section header table?

#define MULTIBOOT_INFO_MEM_MAP          0x00000040 // Is there a full memory map?
#define MULTIBOOT_INFO_DRIVE_INFO       0x00000080 // Is there drive info?
#define MULTIBOOT_INFO_CONFIG_TABLE     0x00000100 // Is there a config table?
#define MULTIBOOT_INFO_BOOT_LOADER_NAME 0x00000200 // Is there a boot loader name?
#define MULTIBOOT_INFO_APM_TABLE        0x00000400 // Is there a APM table?
#define MULTIBOOT_INFO_VIDEO_INFO       0x00000800 // Is there video information?

#ifndef ASM_FILE

typedef unsigned short          multiboot_uint16_t;
typedef unsigned int            multiboot_uint32_t;
typedef unsigned long long      multiboot_uint64_t;

struct multiboot_header
{
    // Must be MULTIBOOT_MAGIC - see above.
    multiboot_uint32_t magic;

    // Feature flags.
    multiboot_uint32_t flags;

    // The above fields plus this one must equal 0 mod 2^32.
    multiboot_uint32_t checksum;

    // These are only valid if MULTIBOOT_AOUT_KLUDGE is set.
    multiboot_uint32_t header_addr;
    multiboot_uint32_t load_addr;
    multiboot_uint32_t load_end_addr;
    multiboot_uint32_t bss_end_addr;
    multiboot_uint32_t entry_addr;

    // These are only valid if MULTIBOOT_VIDEO_MODE is set.
    multiboot_uint32_t mode_type;
    multiboot_uint32_t width;
    multiboot_uint32_t height;
    multiboot_uint32_t depth;
};

// The symbol table for a.out.
struct multiboot_aout_symbol_table
{
    multiboot_uint32_t tabsize;
    multiboot_uint32_t strsize;
    multiboot_uint32_t addr;
    multiboot_uint32_t reserved;
};
typedef struct multiboot_aout_symbol_table multiboot_aout_symbol_table_t;

// The section header table for ELF.
struct multiboot_elf_section_header_table
{
    multiboot_uint32_t num;
    multiboot_uint32_t size;
    multiboot_uint32_t addr;
    multiboot_uint32_t shndx;
};
typedef struct multiboot_elf_section_header_table multiboot_elf_section_header_table_t;

struct multiboot_info
{
    // Multiboot info version number
    multiboot_uint32_t flags;

    // Available memory from BIOS
    multiboot_uint32_t mem_lower;
    multiboot_uint32_t mem_upper;

    // "root" partition
    multiboot_uint32_t boot_device;

    // Kernel command line
    multiboot_uint32_t cmdline;

    // Boot-Module list
    multiboot_uint32_t mods_count;
    multiboot_uint32_t mods_addr;

    union
    {
        multiboot_aout_symbol_table_t aout_sym;
        multiboot_elf_section_header_table_t elf_sec;
    } u;

    // Memory Mapping buffer
    multiboot_uint32_t mmap_length;
    multiboot_uint32_t mmap_addr;

    // Drive Info buffer
    multiboot_uint32_t drives_length;
    multiboot_uint32_t drives_addr;

    // ROM configuration table
    multiboot_uint32_t config_table;

    // Boot Loader Name
    multiboot_uint32_t boot_loader_name;

    // APM table
    multiboot_uint32_t apm_table;

    // Video
    multiboot_uint32_t vbe_control_info;
    multiboot_uint32_t vbe_mode_info;
    multiboot_uint16_t vbe_mode;
    multiboot_uint16_t vbe_interface_seg;
    multiboot_uint16_t vbe_interface_off;
    multiboot_uint16_t vbe_interface_len;
};
typedef struct multiboot_info multiboot_info_t;

struct multiboot_mmap_entry
{
    multiboot_uint32_t size;
    multiboot_uint64_t addr;
    multiboot_uint64_t len;
    #define MULTIBOOT_MEMORY_AVAILABLE              1
    #define MULTIBOOT_MEMORY_RESERVED               2
    multiboot_uint32_t type;
} __attribute__((packed));
typedef struct multiboot_mmap_entry multiboot_memory_map_t;

struct multiboot_mod_list
{
    // the memory used goes from bytes 'mod_start' to 'mod_end-1' inclusive
    multiboot_uint32_t mod_start;
    multiboot_uint32_t mod_end;

    // Module command line
    multiboot_uint32_t cmdline;

    // padding to take it to 16 bytes (must be zero)
    multiboot_uint32_t pad;
};
typedef struct multiboot_mod_list multiboot_module_t;

void parse_multiboot_info(uint32_t magic, multiboot_info_t* mbi);

#endif // ASM_FILE

#endif // MULTIBOOT_HEADER